Polyvinyl chloride-based fibers produced by extrusion-spinning vinyl chloride resins are excellent in, for example, strength, elongation, curl retention, matte properties, and touch, and thus they are used widely as fibers for artificial hair such as hair decoration. Patent Document 1 has proposed a polyvinyl chloride-based fiber produced from a composition that contains a vinyl chloride resin and a matting agent such as a crosslinked vinyl chloride resin. It has been disclosed that this fiber is excellent in touch and appearance (matte properties). However, this fiber is not sufficiently provided with style changeability (properties with which wigs and the like can be changed into various styles with, for example, a brush or a comb: hereinafter, referred to as “style changeability”).
Patent Document 2 has proposed a fiber for artificial hair, in which a surface of the fiber has projected lines in the axial direction of the fiber and the projected lines further have projections and indentations. It has been disclosed that artificial hair products such as wigs using this fiber are excellent in style changeability. However, in Patent Document 2, there is no specific disclosure of a vinyl chloride resin. It should be noted that JP S5-76102A has disclosed a fiber in which the fiber cross section has protrusions in the radial direction. This patent document also has disclosed that this fiber preferably can be used for wigs. However, in this patent document, there is no statement regarding a crosslinked vinyl chloride resin or style changeability.
Patent Document 1: JP H11-50330A
Patent Document 2: JP S56-63006A